| 1. | | Passing an electric current through a certain substance produces oxygen and sulfur. This substance cannot be a(n) Your Answer:| element. | | | An element cannot be broken down into other elements. | | 2. | | Pick the chemical change that occurs when a lit match is held under a piece of metal. Your Answer:| match burns| | | Chemical changes, which release heat and light, occur during the combustion process. | | 3. | | Which identification is incorrect for the elements listed? Your Answer:| Zn, zirconium| | | Zn is zinc; Zr is zirconium. | | 4. | | Which of the following statements is false?
Your Answer:| A theory can be proved correct if sufficient experimental data is acquired. | | | A theory is an explanation of the general principles of a certain phenomenon, with considerable evidence of facts to support it. Although a theory can be proved wrong, it cannot be proved correct, for it is always open to modification. | | 5. | | Which of the following is an intensive quantity? Your Answer:| density of a substance| | | Density does not depend on the amount of substance. | | 6. | | Which number is incorrectly labeled? Your Answer:| 4. 8 x 10-6 mL = 4. 8 microliters| | 1 microliter is equal to 1 x 10-3 mL. | | 7. | | Which of the following properties listed below is an extensive, physical property of sugar? Your Answer:| The length of the edge of an average sugar crystal is less than 1 mm. | | | The length of an edge of a sugar crystal depends on the size of the of sugar crystal in question and is an extensive property. | | 8. | | Which of the following common objects has a mass closest to 1 gram? Your Answer:| a shirt button| | | The typical small shirt button weighs about 1 gram. | | 9. | | Which of the following is an extensive property? Your Answer:| surface area| | The amount of surface area increases with the quantity of material when considering geometrically similar portions. | | 10. | | The symbol for the element potassium is Your Answer:| K| | | K is the symbol for the element potassium. | | 11. | | Which metric prefix name would replace the power of 10 in 3. 68 x 10-3 m? Your Answer:| milli| | | Milli represents 10-3. | | 12. | | The high temperature during a summer day was observed to be 92°F. What was this temperature in °C? Your Answer:| 33| | | You correctly used the following calculation to determine the temperature in °C . | | 13. | | Which one of the following is an extensive property?
Your Answer:| mass| | | Mass is dependent on the size or amount of the sample. | | 14. | | Which of the following statements can be used to describe the study of chemistry? Your Answer:| A chemical theory is developed by testing a hypothesis that tentatively attempts to explain a set of observations and experiments. | | | This general sequence is sometimes called the “scientific method. “| | 15. | | The density of liquid bromine is 3. 12 g/mL. What is the mass of 0. 250 L of bromine? Your Answer:| 780. g| | | | | 16. | | 7. 00 yd3 = ______ m3. Your Answer:| 5. 35| | | | | 17. | | Which set of measurements on a 2. 0-gram standard is the most precise? Your Answer:| 2. 00 g, 2. 01 g, 1. 98 g| | | These measurements are closer to each other than the other choices. | | 18. | | Which conversion to standard exponential notation is incorrect? Your Answer:| 4354 x 10-4 = 4. 354 x 10-1| | Correct Answer:| 0. 00654 x 10-6 = 6. 54 x 10-3| | | | These are equal. | | 19. | | Which of the indicated number of significant figures is incorrect? Your Answer:| 4. 0 x 102 (one significant figure)| | | This number has two significant figures. | | 20. | | An object will sink in a liquid if the density of the object is greater than that of the liquid.
If the mass of an object is 9. 83 g, what volume must it have in order for it to sink in liquid mercury (density = 13. 6 g/cm3)? Your Answer:| less than 0. 723 cm3| | | | | 21. | | One mg/cm2 equals ______ kg/m2. Your Answer:| 10-2| | | | | 22. | | What is the volume of a bar of metal with the dimensions 2. 0 m x 20. 0 dm x 20. 0 cm? Your Answer:| 8. 0 x 102 dm3| | | The measurements have been converted to dm. | | 23. | | Which of the following objects is the most dense? Your Answer:| an object with a volume of 2. 5 L and a mass of 12. 5 kg| | Correct Answer:| an object with a volume of 3. 91 x 10-24 nm3 and a mass of 7. 93 x 10-14 ng| | | The density is 0. 50 g/mL. There is another choice that has a denser object. | | 24. | | Which of the following numbers is incorrectly rounded off to three significant figures? Your Answer:| 1213 rounded to 1. 213 x 103| | | This has four significant figures. | | 25. | | The distance from Earth to the Moon is approximately 240,000 miles. The Concorde SST has an airspeed of about 2. 40 x 10 3 km/hr. If the Concorde could fly to the Moon, how many hours would it take, ignoring gravity? Your Answer:| 1. 6 x 102 hours| | | Using two significant figures, this is 6. 7 days. | | 26. | | How many dozens of particles of dust are in 2. 5 grams if each dust particle has a mass of 2. 51 x 10-4 grams? Your Answer:| 813 dozen| | | There are about 9760 dust particles. | | 27. | | Zinc has a density of 446 lb/ft3. What is the density of zinc in g/cm3? Your Answer:| 7. 14 g/cm3| | | 1 lb = 453. 6 g and 1 ft = 30. 48 cm or 1 ft3 = 28317 cm3. | | 28. | | A spherical ball of lead has a diameter of 5. 0 cm. What is the mass (in grams) of the sphere if lead has a density of 11. 34 g/cm3? Note: The volume of a sphere is V = (4/3)r3. Your Answer:| 7. 4 x 102 grams| | | The volume is 65 cm3. | | 29. | | Which number of significant figures is incorrect? Your Answer:| 0. 00050 (five)| | This is incorrect since the first four zeros do not count. The correct number of significant figures is two. | | 30. | | The average distance from the Earth to the Moon, 383,000,000 m, can also be expressed as Your Answer:| 3. 83 x 1010 cm. | | | All the zeros and the 83 should be counted when determining exponential notation. | | 31. | | Which of the following is a physical change? Your Answer:| boiling water| | | Phase changes are physical changes. In this example, water changes from the liquid state to the gas state. | | 32. | | Which of the following is a homogeneous mixture? Your Answer:| nitrogen| | Correct Answer:| air| | | Nitrogen is a pure substance. | | 33. | | A temperature of 63°F is _______ K. Your Answer:| 290| | | 63°F = 17°C = 290 K. | | 34. | | Which of the following numbers contains six significant figures? Your Answer:| 1000. 00| | | All zeros in this number are significant. | | 35. | | Which is not correctly represented by the right number of significant figures? Your Answer:| ((2. 70/3. 00) -2. 0) x (1. 20) = -1. 32| | | The answer should only have two significant figures. | | 36. | | A cylindrical glass tube 15. 0 cm in length is filled with ethanol. The mass of ethanol needed to fill the tube is found to be 9. 64 g.
Calculate the inner diameter of the tube in centimeters. (The density of ethanol is 0. 789 g/mL. ) Your Answer:| 0. 509 cm| | Correct Answer:| 1. 02 cm| | | | This is the radius. You obviously understand the calculation. | | 37. | | 5. 00 in. is _______ mm. Your Answer:| 127| | | 1. 00 in. = 25. 4 mm| | 38. | | A cube of plastic 1. 5 cm on each side has a mass of 1. 9 g. What is its density in g/cm3? Your Answer:| 1. 78 g/cm3| | Correct Answer:| 0. 56 g/cm3| | | | This is cm3/g. | | 39. | | The winner of a 10,000-m road race completed the course in exactly 20 minutes, 13 seconds. What was the winner’s average speed in miles per hour?
Your Answer:| 18. 64 mph| | | 20 minutes, 13 seconds = 0. 34 hours, and 10,000 m = 6. 2 miles. | | 40. | | A hypothesis Your Answer:| is a consistent interpretation of many related observations, experiments, and predictions. | | Correct Answer:| may be changed due to unexpected experimental results. | | | | This consistent interpretation is a theory. | | 41. | | Which of the statements below gives the correct relationship between units? Your Answer:| 1000 mA ; 1 nA| | Correct Answer:| 10 mg ; 1 dg| | | | 1000 mA is 1 A, while 1 nA is one-billionth of an A. | | 42. | | Which of the following is a homogeneous mixture?
Your Answer:| gasoline| | | You cannot see the various compounds in gasoline. | | 43. | | Which of the following processes does not represent a physical change? Your Answer:| exploding dynamite| | | This is a chemical reaction, with new products being formed. | | 44. | | Perform the indicated operations and express the answer with the proper number of significant digits. 28. 1 cm + 0. 53 cm + 75. 321 cm = Your Answer:| 104. 0 cm| | | This number has one figure to the right of the decimal point and matches the quantity having the fewest digits to the right of the decimal point in the question. | | 45. | Which of the following is a chemical process? Your Answer:| tarnishing of silver| | | The silver forms a new chemical by oxidization. | | 46. | | Which one of the following is a physical process? Your Answer:| the condensation of water vapor| | | Only the physical state of water is changing. | | 47. | | For a given temperature, how do the Fahrenheit and Celsius values compare? Your Answer:| Fahrenheit values are higher than Celsius values above -40, and lower than Celsius below -40. | | | Fahrenheit degrees span less thermal energy change than Celsius degrees, and therefore rise from -40 and fall from -40 at a faster rate. | 48. | | How many grams of alcohol with a density of 0. 900 g/cm3 will have the same volume as 20. 0 g of mercury, with a density of 13. 6 g/cm3? Your Answer:| 1. 32| | | Mercury is very dense, so a small volume has a large mass. | | 49. | | A student performs an experiment to determine the freezing point of water. Three values are obtained: -2. 0°C, -2. 2°C, and -2. 1°C. The thermometer has a mark for each degree. Which of the following statements is true? Your Answer:| These values are precise but not accurate. | | | The values are close to one another but the previously known freezing point of water is 0. 0 °C. | |